Whitebeard's death from One Piece.
Not only does he reveal the whole point of the series (The One Piece, the treasure all the pirates are out at sea trying to find) does indeed exists we also find out through his entire life he did not receive a single wound from running away. He also managed to get what he always dreamed of, a family.

true: dbz was and will always be
the cornerstone to all great martial arts anime's...
at least thats my opinion

Goku vs Buu, *Naruto vs Sasuke (both the one at the hospital and the one in the Valley)
Wolf's Rain- Kiba vs Darcia, **SAsuke vs Itachi, ***Goku vs Majin Vegeta,
Ichigo vs ****Byakuya Kuchiki... and last but certainly not least When *****Gohan turned Super Saiyan 2 for the first time: That was
one of the most touching moments in the whole entire Series etc.